Transmission

ABSTRACT

The illustrated two-speed accessory drive transmission includes centrifugal clutch shoes and a planetary friction unit, with spring means for urging the shoes into frictional driving contact with a clutch drum and thereby actuating the planetary unit during low engine speeds for driving the output member in overdrive, and a one-way clutch for interconnecting the output and input in a direct drive relationship upon disengagement of the shoes from the clutch drum under the action of centrifugal force, with a pin or roller mounted between an input member and a ramp formed on the clutch shoes to control disengagement of the clutch at a first predetermined speed and the reengagement thereof at a lower predetermined speed than the first predetermined speed, in both instances without undue slippage.

United States Patent Merrell et al. 1 Nov. 6, 1973 TRANSMISSION2,514,228 7/1950 Dodge 192 104 (3 Inventors: Richard L e u 3,702,08411/1972 Kepple et a]. 74/752 E ky i g k f Primary Examiner-Charles J.Myhre ar epp a 0 Assistant Examiner-Thomas C. Perry 10 Att0rney-WarrenE. Finken et a1. [73] Assignee: General Motors Corporation,

Detroit, Mich. [57] ABSTRACT [22] Fied: Man 3, 1972 The illustratedtwo-speed accessory drive transmission lncludes centrlfugal clutch shoesand a planetary fr1c- [21] Appl- NOJ 231,504 tion unit, with springmeans for urging the shoes into frictional driving contact with a clutchdrum and 52 us. 01 74/752 E, 192/104 c i g i Planetary F' l "3 51 1111.C1. Fl6h 5/60, F16d 43/22 Spec 5 Vmgt efutPutmem f "veian [58] Field ofSearch 192/104 C, 104 B, f dF g "i f fi mg tge output and 192/104 R 103B; 74,752 E 1nput1n a lrect r1ve re at1ons 1p upon lsengagement of theshoes from the clutch drum under the act1on of 15612:"$32111insist/i3:32121511112:35 312 2112: UNITED STATES PATENTS shoesto control disengagement of the clutch at a first R predetermined peedand the regngagement thereof at g g 1 a lower predetermined speed thanthe first predetero ge 2,432,591 12/1947 Schuckers l 4 I I 192/104 Rmined speed, 1n both 1nstances w1thout undue sl1ppage. 2,455,435 12/1948Nader et a1. 192/104 C X 16 Claims, 7 Drawing Figures PATENTEBRUY 6 maSHEET 2 BF 2 I600 INPUT SPEED RPM TRANSMISSION This invention relatesgenerally to transmissions and, more particularly, to two-speedtransmissions.

This invention provides an improved transmission for driving engineaccessories at two different speed ratios with respect toengine speed,while having the clutch thereof disengage at high speeds and reengage atsubstantially lower speeds. More specifically, it may be desirable toincrease the speed of an engine accessory, such as the air injectionpump, to increase pumping capacity at low engine speeds and then, at apredetermined higher engine speed, to drive the accessory at a 1:1 speedratio therewith to reduce further increase in pumping capacity, and thento retain the lower pumping capacity to a particular speed lower thanthe abovedescribed predetermined higher engine speed.

Accordingly, an object of the invention is to provide improved means foroperating various engine accessories at two different speed ratios withrespect to engine speed with different controlled change-over speedsduring acceleration and deceleration.

Another object of the invention is to provide improvedcentrifugally-actuated engaging and disengaging means for controllingthe engaging and disengaging operations between the input and a ballfriction planetary unit over predetermined speed ranges such that thereleasing speed is a predetermined amount higher than the engaging speedin order to eliminate hunting when the speed changes are small.

A further object of the invention is to provide an im-. provedspring-loaded centrifugal weight means for disconnecting a ballplanetary drive unit from the input and actuating a one-way clutch at afirst predetermined engine speed, and reconnecting the planetary driveunit with the input at a second lower predetermined engine speed.

A still further object of the invention is to provide spring-loadedcentrifugal clutch shoes cooperating with a roller and ramp mechanismfor disconnecting a friction clutch and a ball planetary drive unit fromthe input without undue slippage therebetween and actuating a one-wayclutch at a first predetermined engine speed, and reengaging the clutch,again, without undue slippage, and, hence, reactivating the planetarydrive unit at a second lower predetermined engine speed.

These and other objects and advantages of the invention will be apparentwhenreference is made to the following description and accompanyingdrawings, wherein:

FIG. I is a fragmentary cross-sectional view of an accessory drivemechanism embodying the invention;

FIG. 2 is a cross-sectional view taken along the plane of line 22 ofFIG. 1, as if FIG. 1 were a full round view, and looking in thedirection of the arrows;

FIG. 3 is an enlarged fragmentary cross-sectional view taken along theplane of line 3-3 of FIG. 1, as if FIG. 1 were a full round view, andlooking in the direction of the arrows;

FIG. 4 is an enlarged fragmentary cross-sectional view of a portion ofthe FIG. 2 structure in a different operational position from that ofFIG. 2;

FIG. 5 is a graphic representation of operational characteristics of theinvention;

FIG. 6 is a fragmentary cross-sectional view of a modification of aportion of the FIG. 1 structure; and

FIG. 7 is a cross-sectional view takenalong the plane of line 7-7 ofFIG. 6, as if FIG. 6 were a full round view, and looking in thedirection of the arrows.

Referring now to the drawings in greater detail, FIG. 1 illustrates atwo-speed accessory drive mechanism 10 including an output or accessorydrive shaft 12 suitable for connection with a predetermined engineaccessory, represented generally at 14, such as an air injection pump.The shaft 12 is rotatably mounted in bearings 16 supported within apulley hub 18.. The accessory drive shaft 12 includes a centralpassageway 20 and a recessed end portion 22. An internally threadedextended shaft end 24 of the accessory drive mechanism 10 is inserted inthe recess 22 and secured therein by a bolt 26 extending through thecentral passageway 20 and threadedly connected to the internallythreaded shaft end 24. A washer 28 is mounted between a head 30 of thebolt 26 and the end face 32 of the, accessory drive shaft 12.

An input pulley 34, driven by a belt 36 and including an inwardlyextending flange 38, is secured toan outwardly extending flange 40formed on the pulley hub 18 by bolts 42 mounted through aligned openings44 and 45 formed in the flanges 38 and 40, respectively,

the bolts 42 being threadedly secured to a cup-shaped rotatable housingmember 46 whose end face 47 abuts against the adjacent face 48 of theflange 40.

A centrifugal clutching arrangement 49 is mounted in the housing member46. The arrangement 49 includes a clutch drum 50 mounted on needlebearings 52 around a sleeve extension 54 of the pulley hub 18, thesleeve extension 54 being mounted on needle bearings 56 around theoutput shaft 12. A pair of centrifugal clutch shoes 58, includingfrictional linings 60 bonded to their radially inner surfaces 61, ismounted around the clutch drum 50, the shoes 58 being urged toward thedrum 50 by springs 62 (FIG. 2) interconnected between oppositelydisposed ends of the shoes 58.

Converging ramps 64 and, 66 (FIG. 2) are formed on the radially outersurface 67 of each shoe 58 at an intermediate location thereon. A ramppin or roller 68 is mounted in each set of converging ramps 64'and 66formed in each shoe 58 and retained radially in a pocket 69 formed inthe inner surface 70 of the housing member 46. A cover 71 is secured bybolts 72 to the end face of the housing member 46, axially retaining theramp pins 68.

A flanged extension 73 is either secured to or formed on the clutch drum50 so as to extend around an intermediate portion of the output shaft12. The flanged extension 73 may be formed of steel and secured to theclutch drum 50 which may be formed of cast iron, or the extension 73 maybe formed integrally with the clutch drum 50 and formed of a singleselected material. A plurality of axial slots 74 are formed on the endof the flanged extension 73.

A carrier member 76 of a planetary friction drive mechanism 78 includesinternally formed ribs 80 which mesh with the axial slots 74 on theclutch drum extension 73. A sun member 82 of the planetary frictiondrive mechanism 78 is formed integrally with the accessory drive shaft12. A fixed housing member 84 is mounted around the flanged extension73, with a suitable seal 86 mounted therebetween. An outer ring retainer88 is formed on the housing member 84 to radially confine an outer ringmember 90 of the planetary unit 78. Toroidal surfaces 92 and 94 areformed on oppositely disposed portions of the sun member 82 and theouter ring member 90, respectively, providing for the mounting thereinof ball planet pinions 96 and the axial alignment of the sun member 82and the outer ring member 90. The ball planet pinions 96 are mounted inthe toroidal surfaces 92 and 94 such that the preload thereacross is apredetermined amount, depending upon the application involved. The ballplanet pinions 96 are separated and driven by equally spaced fingers 98extending axially from the carrier member 76. Inserts or shoes 99 (FIG.3) having aluminum or other suitable linings 100 bonded thereon may beinserted on opposite sides of each ball planet pinion 96 so as to beslidably and rotatably mounted against the adjacent fingers 98 forbetter alignment and wear characteristics.

The outer ring member 90 is retained against a shoulder 101 (FIG. 1)formed on the inner surface 102 of the outer ring retainer 88 by aretaining clamp 103 secured to the end face 104 of the outer ringretainer 88 by bolts 105, and abutted against the adjacent face 106 ofthe outer ring member 90.

An end cover 107 is secured to the fixed housing member 84 by means ofbolts 108 and a gasket 109. A separate end cap 110 covers a centralopening 112 in the end cover 107 and is secured thereto by bolts 113,providing access to the bolt 26.

A one-way clutch 114 is mounted around the output shaft 12 within thesleeve extension 54 of the pulley hub 18, intermediate the bearings 16and 56.

OPERATION In operation, the input pulley 34 is rotated by the belt 36from a suitable prime mover, such as the engine crankshaft (not shown),rotating the pulley hub 18 and its sleeve extension 54 and theinterconnected rotatable housing member 46 therewith. At engine speedsbelow a predetermined value, the springs 62 (FIG. 2) urge thecentrifugal clutch shoes 58 into contact with the clutch drum 50. Thecentrifugal clutch shoes 58, as well as the clutch drum 50 to which theyare connected by the linings 60, are driven by means of the ramp pins 68which will have rolled up the ramp 64 to become wedged between the ramp64 and the inner surface 70 of the housingmember 46. Such rotation ofthe clutch drum 50 and its flanged extension 73 drives the carriermember 76 via the ribs 80-and-slots 74 connection therebetween. Inasmuchas the outer ring member 90 is fixed by the outer ring retainer retainer88 of the fixed second housing member 84, the ball planet pinions 96 arerotated by the carrier member 76 and caused to walk around within theouter ring member 90. Such rotation of the ball planet pinions 96 causesthe sun member as well as the integrally-formed output shaft 12 torotate therewith at a predetermined increased speed with respect to thespeed of the carrier member 76, depending upon the radii involved. Thisserves to drive the selected engine accessory 14 at the increased sunmember 82 speed, as compared to the input speed of the pulley 34.

Once a predetermined engine speed has been reached, the centrifugalclutch shoes 58 will be urged radially outwardly under the action ofcentrifugal force against the force of the springs 62. When suchdisengagement from the clutch drum 50 has begun, and the ramp pins 68are forced down into the bottom of the converging ramps 64 and 66,complete disengagement will occur without significant slippage becausethat portion of the normal load due to the wedging action will haverapidly decreased at this point, the carrier member 76 and the sunmember 82 will begin toslow down until such time as the output shaft 12,on which the sun member 82 is formed, has attained the slower speed ofthe input pulley 34 and the pulley hub 18. At the latter speed, theoutput shaft 12 will be caused to continue to rotate at the input speedby the one-way clutch 114, thereby causing the selected engine accessory14 to continue to rotate at a 121 speed ratio with the input pulley 34throughout all higher engine speeds.

Now, more specifically with respect to the roller 68- ramp 64arrangement, the housing member 46 is driven by the pulley 34 below apredetermined speed, say, 1,900 rpm, the reaction torque on the drum 50,which is engaged by the centrifugal clutch shoes 58, causes a wedgingaction on the rollers or pins 68 (FIG. 4). This wedging action resultsin an induced normal force between the shoes 58 and the drum 50 which,in turn, keeps the clutch 49 engaged. The induced normal force is afunction of the wedge angle 6 (FIG. 4) and the coefficient of frictionbetween the pins 68 and the centrifugal clutch shoes 58 and, as such,can be controlled to make the clutch 49 self-energizing. Specifically,the induced normal load is equal to the torque transmitted between thelinings 60 of the shoes 58 and the drum 50 divided by the drive radiusthereof, modified by a load factor of cot 0 minus the pin-shoecoefficient of friction and divided by one plus the coefficient offriction times cot 0. It may be noted that the force of the springs 62is sufficient to keep the clutch 49 engaged during start- Thecentrifugal load resulting from the action of centrifugal force on thecentrifugal clutch shoes 58, offset by the force of the springs 62, inconjunction with the abovedescribed wedging effect, is such that the netnormal clutch load thereof will serve to keep the clutch 49 engaged upto the predetermined engine speed of 1,900 rpm, and thereafter urge theshoes 58 away from the drum 50. One of the design criteria of thisclutch 49 is that the net normal clutch load, due to centrifugal loadand spring force, is zero" at a predetermined lower engine speed, say,1,600 rpm.

Other criteria are that the normal force induced by the wedging effectis greater than the normal force required to transmit the reactiontorque between the centrifugal clutch shoes 58 and the drum 50, and thatthe reaction torque increases with increased speed of the drum 50.

The clutch 49 load characteristics vs. input speed are illustratedgraphically in FIG. 5. The normal clutch load (Curve A) is the loadrequired to drive without slippage occurring between the centrifugalclutch shoes 58 and the drum 50. The product of this load, thecoefficient of friction between the linings 60 and the drum 50, and thedrive surface radius determines the amount of torque that can betransmitted, or stated another way, the normal clutch load required totransmit a given torque equals that torque divided by the product of thecoefficient of friction and the drive radius.

The applied normal clutch load (Curve B) is the sum of the inducednormal load (Curve C) resulting from the wedging effect of theroller-ramp system described above and the force (Curve D) of thesprings 62 less the centrifugal load (Curve E) due to the action ofcentrifugal force on the clutch shoes 58. As the drive speed increasestoward the above-mentioned 1,900 rpm, the required normal clutch load(Curve A) remains less than the applied load (Curve B), and. the clutch49 remains engaged. At the latter speed, the centrifugal clutch shoes 58begin to pull away from the drum 50 under the action of centrifugalforce, and

the clutch 49 starts to slip with the result that the drum 50 begins toslow down. This, of course, serves to reduce the applied normal clutchload (Curve B), and the reaction torque decreases with the decreasingspeed of the drum 50. Once disengagement has begun, completedisengagement will occur rapidly and without excessive slippage becausethat portion of the normal load due to the wedging action is rapidlydecreasing. It should be noted that such disengagement would occurautomatically should the torque reach substantially zero for any reason,above a predetermined speed.

Specifically, once the centrifugal force (Curve E) becomes greater thanthe sum of the force of the springs 62 (Curve D) and the induced normalload (Curve C), such as would occur at 1,900 rpm, the centrifugal clutchshoes 58 move out against the inner surface 70 of the housing 46, andthe clutch 49 is disengaged. It may be noted in FIG. 4 that each rolleror pin 68 remains in the pocket 69 while the adjacent shoe 58 is forcedto rotate in a clockwise direction to move the junction of the ramps 64and 66 into contact with the pin 68.

As the drive speed decreases from the above drive speed of 1,900 rpm,the resultant normal clutch load equals thenet force between thecentrifugal load of the centrifugal clutch shoes 58 and the force of thesprings 62, the induced normal force being zero at this time since theclutch 49 is disengaged. At the predetermined lower drive speed of 1,600rpm, the spring force (Curve D) equals the centrifugal load (Curve E),and the centrifugal clutch shoes 58 are pulled by the springs 62 backinto contact with the drum 50, the shoes 58 rotating in acounter-clockwise direction, as illustrated in FIG. 4, as a result ofthe ramp 64and pin 68 contact, and the clutch 49 is reengaged.

Once the engagement process has begun, engagement will be completedrapidly and without undue slippage because the portion of the normalload due to the wedging action is suddenly'added to the total normalload.

FIG. 6 Embodiment The FIG. 6-7 transmission arrangement 120 is generallysimilar to the FIG. l-2 arrangement, and common elements bear the samereference numerals, except that a wedge and slot system is used in lieuof the rollerramp system. Specifically, a rectangular-shaped wedge 122(FIG. 7) is mounted in adjacent slots 124 and 126 (FIG. 6) formed atpredetermined angles in the housing 46 and the clutch shoes 58,respectively.

' Referring to FIG. 6, the drive would be in a clockwise direction withreaction torque being in a counterclockwise direction. Each of the slots124 and 126 includes diverging side walls so as to permit the rocking ortilting action required of the wedge 122 as the shoes 58 move generallyradially and slightly rotationally under the action of centrifugal forceto effectuate the alternating contacts between the linings 60 and thedrum 50, and between the shoes 58 and the housing 46, in a mannersimilar to that described above relative to FIG. 4.

Air Cooling System Referring now to FIG. 1, it may be noted that thedrum 50-lining 60 contacting surfaces are continuously cooled by airdrawn by the pulley 34, by virtue of the latters pumpingcharacteristics, from between the housing 84 and the cover member 71 ofthe housing 46, through an opening 130 formed in the cover 71 adjacentone end of the drum 50-liining 60 and thence through a plurality ofoutwardly tapered openings 132 to a plurality of axial openings 134formed in the housing 46 adjacent the other end of the drum 50-lining 60surfaces, and out between the housing 46 and the pulley flange 38.

Lubrication System Referring again to FIG. 1, it may be noted that afluid medium, such as a suitable oil, contained within the stationaryhousing 84/ 107 is picked up by the carrier member 76, serving as aslinger and having a scoop-like configuration 136 formed on the radialouter edge thereof, thrown radially outwardly along one side of the sunmember 82, the ball planets 96, and the outer ring 90, onto the outerring retainer 88 and through a plurality of radial openings 138 formedin the latter, into an outer chamber 140, from whence the oil flowsinwardly under the force of gravity along the other side of theouterring 90, along and between the ball planets 96 and along the otherside of the sun member 82 to a contoured surface 142 formed on the endcap which directsthe oil into a plurality of outwardly tapered openings144 formed through the sun member 82 toward the carrier member 76 for anew cycle.

It should be apparent that the invention provides an improved ballplanetary drive coordinated with centrifugal clutch shoes whichaltematelly engage and disengage a clutch drum to respectively drive andrelease an interconnected carrier memberof the planetary unit, while aroller-ramp system, or a wedge-slotsystem, cooperates with the clutchshoes to efficiently control the disengagement at a predetermined enginespeed and the re-engagement at a lower predetermined speed.

It should be further apparent that, if desired for a particularapplication, the elements could be rearranged such that the pulleyserves as an output member with the belt driving any selected engineaccessory, and the output shaft serves as an input shaft, being drivenby any suitable prime mover. In order to accomplish this bidirectionalfeature, it would be essential that the angle of the ramp 66 be designedto function in the same manner as was described above relative to theangle 0 of the ramp 64.

While but two embodiments of the invention have been shown anddescribed, other modifications thereof are possible.

We claim:

1. A transmission comprising input and output means; a planetary drivevunit including a first member mounted for rotation with said outputmeans, a reaction member, intermediate traction members friction allycontacting said first and reaction members, and a carrier member fordriving said traction members; centrifugally-actuated clutch means foroperatively connecting said carrier member to said input means;resilient means for urging said centrifugally-actuated clutch means intooperational engagement with said carrier member below a predeterminedinput speed; one-way clutch means operatively connected between saidinput and output means for operatively connecting said input means tosaid output means for direct drive of said output means at all inputspeeds above said predetermined input speed upon saidcentrifugallyactuated clutch means becoming operatively disengaged withrespect to said carrier member in response to the action of centrifugalforce; and control means responsive to torque and operating directlybetween said input means and said centrifugally-actuated clutch meansfor producing a substantially radial force causing the reengagement ofsaid centrifugally-actuated clutch means to occur at a lowerpredetermined speed than said above-mentioned predetermined input speed.

2. A transmission comprising input and output means; a planetary driveunit including a first member mounted for rotation with said outputmeans, a reaction member, intermediate traction members frictionallycontacting said first and reaction members, and a carrier member fordriving said traction members; centrifugally-actuated clutch means foroperatively connecting said carrier member to said input means;resilient means for urging said centrifugally-actuated clutch means intooperational engagement with said carrier member below a predeterminedinput speed; one-way clutch means operatively connected between saidinput and output means for operatively connecting said input means tosaid output means for direct drive of said output means at all inputspeeds above said predetermined input speed upon saidcentrifugallyactuated clutch means becoming operatively disengaged withrespect to said carrier member in response to the action of centrifugalforce; and roller-ramp means responsive to to torque and operatingdirectly between said input means and said centrifugallyactuated clutchmeans for producing a force component directed at a predetermined anglewith respect to the axis of said clutch means causing the reengagementof said centrifugally-actuated clutch means to occur at a lowerpredetermined speed than said abovementioned predetermined input speed.

3. The transmission described in claim 2, wherein said roller-ramp meansincludes a ramp of a predetermined angle formed on the radial outersurface of said centrifugally-actuated clutch means, and a rollermounted intermediate said ramp and said input means.

4. A transmission comprising input and output means; a planetary driveunit including a first member mounted for rotation with said outputmeans, a reaction member, intermediate traction members frictionallycontacting said first and reaction members, and a carrier member fordriving said traction members; a clutch drum rotatably mounted on saidinput means and connected for rotation with said carrier member; a pairof oppositely disposed centrifugally-actuated clutch shoes mountedaround said clutch drum; resilient means for urging saidcentrifugally-actuated clutch shoes into frictional engagement with saidclutch drum below a predetermined input speed; one-way clutch meansoperatively connected between said input and output means foroperatively connecting said input means to said output means for directdrive of said output means at all speeds above said predetermined inputspeed upon said centrifugally-actuated clutch shoes becoming operativelydisengaged from said clutch drum in response to the action ofcentrifugal force; and control means responsive to torque andoperatively connected between said input means and saidcentrifugally-actuated clutch shoes for producing a force componentdirected at a predetermined angle with respect to the axis of saidclutch shoes causing the reengagement of said centrifugally-actuatedclutch shoes with said.

clutch drum at a lower predetermined speed than said above-mentionedpredetermined input speed.

5. The transmission described in claim 4, wherein said control meansincludes a ramp of a predetermined angle formed on the radial outersurface of each of said clutch shoes, and a pin rotatably mountedintermediate each of said ramps and said input means.

6. A transmission comprising an output shaft; an input pulley assemblyincluding a pulley hub rotatably mounted on said output shaft, an inputpulley secured to said pulley hub, and a sleeve member formed on saidpulley hub and rotatably mounted on said output shaft; a planetary driveunit including a fixed housing, a sun member mounted for rotation withsaid output shaft, an outer ring member secured to said fixed housing,intermediate ball members frictionally contacting said sun and outerring members, and a carrier member for driving said ball members; arotatable housing secured to said pulley hub, a clutch drum rotatablymounted on said sleeve member and connected for rotation with saidcarrier member; a pair of oppositely disposed centrifugally-actuatedclutch shoes mounted around said clutch drum; spring means for urgingsaid centrifugally-actuated clutch shoes into frictional engagement withsaid clutch drum below a predetermined input speed; one-way clutch meansoperatively connected between said sleeve member and said output shaftfor operatively connecting said input pulley assembly to said outputshaft for direct drive of said output shaft at all speeds above saidpredetermined input speed upon said centrifugally-actuated clutch shoesbecoming disengaged from said clutch drum in response to the action ofcentrifugal force; and control means operatively connected between saidrotatable housing and said centrifugally-actuated clutch shoes forretaining said centrifugally-actuated clutch shoes in the disengagedposition until a lower predetermined speed than said above-mentionedpredetermined input speed is attained, said control means including aramp of a predetermined angle formed on the radial outer surface of eachof said clutch shoes, a pocket formed on the radial inner surface ofsaid rotatable housing, and a pin rotatably mounted intermediate each ofsaid ramps and said pocket.

7. The transmission described in claim 6, and an air cooling system forautomatically cooling said clutch drum and said clutch shoes.

8. The transmission described in claim 7, wherein said air coolingsystem includes an opening formed in said rotatable housing adjacentsaid fixed housing, a first plurality of tapered openings formed throughsaid clutch drum, and a second plurality of tapered openings formed insaid rotatable housing adjacent said pulley hub, said pulley assemblyserving as a pump to continuously draw air through all of said openingsto cool said clutch drum and said clutch shoes.

9; The transmission described in claim 6, and a lubrication system forsaid planetary drive unit.

10. The transmission described in claim 9, wherein said lubricationsystem includes a predetermined volume of a fluid medium contained insaid fixed housing, slinger means formed on the radial outer edge ofsaid carrier member, a plurality of radial openings formed in theportion of said fixed housing supporting said outer ring member, achamber formed intermediate said portion of said fixed housing and theouter wall of said fixed housing, a contoured portion formed on an innerend surface of said fixed housing adjacent said sun member, and aplurality of tapered openings formed through said sun member, saidcarrier member and said slinger means serving to project said fluid medium radially outwardly through said radial openings into said chamberfrom whence said fluid medium returns under the force of gravity to saidcontoured portion, said contoured portion directing said fluid mediuminto said tapered openings for pickup by said carrier member.

11. The transmission described in claim 6, wherein said input pulleyassembly serves as an output means, said output shaft serves as an inputshaft.

12. The transmission described in claim 4, wherein said control meansincludes wedge and slot means operatively mounted between said inputmeans and said centrifugallyactuated clutch shoes.

13. The transmission described in claim 12, wherein said wedge and slotmeans includes a first pair of oppositely disposed slots each havingdiverging side walls formed at predetermined angles in said input means,a second slot having diverging side walls formed at predetermined anglesin each of said clutch shoes adjacent said respective first pair ofslots, and a wedge mounted in each of said adjacent sets of first andsecond slots.

14. The transmission described in claim 13, wherein said wedges arerectangularly shaped with the edges along the length thereof beingrounded off and said rounded-off edges being mounted in adjacent firstand second slots for tilting therein as required to accommodate thegenerally radial movement of said clutch shoes under the action ofcentrifugal force to effectuate the alternating contacts between saidinput means reaction member and said clutch shoes and between saidclutch shoes and said clutch drum at said different predeterminedspeeds.

15. A transmission comprising input and output means;centrifugally-actuated clutch means for operatively connecting saidinput and output means when engaged; resilient means for normallycausing said centrifugally-actuated clutch means to remain engaged belowa predetermined input spec-d; and control means responsive to torque andoperating directly between said input means and saidcentrifugally-actuated clutch means and including, means for producing asubstantially radial engaging force resulting in the reengagement ofsaid centrifugally-actuated clutch means to occur at a lowerpredetermined speed than said abovementioned predetermined input speed.

16. A transmission comprising an input member; an output member; a hubmember intermediate said input and output members; a rotatable housingsecured to said input member, a clutch drum rotatably mounted on saidhub member and operatively connected to drive said output member; a pairof oppositely disposed centrifugally-actuated clutch shoes mountedaround said clutch drum; spring means for urging saidcentrifugally-actuated clutch shoes into frictional engagement with saidclutch drum below a predetermined input speed; and control meansoperatively connected between said rotatable housing and saidcentrifugallyactuated clutch shoes for retaining saidcentrifugallyactuated clutch shoes in the disengaged position until alower predetermined speed than said abovementioned predetermined inputspeed is attained, said control means including a ramp of apredetermined angle formed on the radial outer surface of each of saidclutch shoes, a pocket formed on. the radial inner surface of saidrotatable housing, and a pin rotatably mounted intermediate each of saidramps and said pocket.

1 and that said Letters Patent arehereby corrected as shown below:

12 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3, 769 858Dated November 6, i973 Richard L. Merrell, Lubomyr O. Hewko, andInventorfl's) Richard K. Kepgle Patent 'No It is certified that errorappears in the above-identified patent I" I I Column 9, Claim l4', line40, delete "reaction":

Column 10, Claim 14, line 1, delete "member".

Signed and sealed this lLflZh day of May 197M.

(SEAL) e Attestz v C V v EDWARD l-LFLETCHER R. c. MARSHALL DANNAttesting Officer I Commissioner of Patents

1. A transmission comprising input and output means; a planetary driveunit including a first member mounted for rotation with said outputmeans, a reaction member, intermediate traction members frictionallycontacting said first and reaction members, and a carrier member fordriving said traction members; centrifugally-actuated clutch means foroperatively connecting said carrier member to said input means;resilient means for urging said centrifugally-actuated clutch means intooperational engagement with said carrier member below a predeterminedinput speed; one-way clutch means operatively connected between saidinput and output means for operatively connecting said input means tosaid output means for direct drive of said output means at all inputspeeds above said predetermined input speed upon saidcentrifugally-actuated clutch means becoming operatively disengaged withrespect to said carrier member in response to the action of centrifugalforce; and control means responsive to torque and operating directlybetween said input means and said centrifugally-actuated clutch meansfor producing a substantially radial force causing the reengagement ofsaid centrifugallyactuated clutch means to occur at a lowerpredetermined speed than said above-mentioned predetermined input speed.2. A transmission comprising input and output means; a planetary driveunit including a first member mounted for rotation with said outputmeans, a reaction member, intermediate traction members frictionallycontacting said first and reaction members, and a carrier member fordriving said traction members; centrifugally-actuated clutch means foroperatively connecting said carrier member to said input means;resilient means for urging said centrifugally-actuated clutch means intooperational engagement with said carrier member below a predeterminedinput speed; one-way clutch means operatively connected between saidinput and output means for operatively connecting said input means tosaid output means for direct drive of said output means at all inputspeeds above said predetermined input speed upon saidcentrifugally-actuated clutch means becoming operatively disengaged withrespect to said carrier member in response to the action of centrifugalforce; and roller-ramp means responsive to to torque and operatingdirectly between said input means and said centrifugally-actuated clutchmeans for producing a force component directed at a predetermined anglewith respect to the axis of said clutch means causing the reengagementof said centrifugally-actuatEd clutch means to occur at a lowerpredetermined speed than said abovementioned predetermined input speed.3. The transmission described in claim 2, wherein said roller-ramp meansincludes a ramp of a predetermined angle formed on the radial outersurface of said centrifugally-actuated clutch means, and a rollermounted intermediate said ramp and said input means.
 4. A transmissioncomprising input and output means; a planetary drive unit including afirst member mounted for rotation with said output means, a reactionmember, intermediate traction members frictionally contacting said firstand reaction members, and a carrier member for driving said tractionmembers; a clutch drum rotatably mounted on said input means andconnected for rotation with said carrier member; a pair of oppositelydisposed centrifugally-actuated clutch shoes mounted around said clutchdrum; resilient means for urging said centrifugally-actuated clutchshoes into frictional engagement with said clutch drum below apredetermined input speed; one-way clutch means operatively connectedbetween said input and output means for operatively connecting saidinput means to said output means for direct drive of said output meansat all speeds above said predetermined input speed upon saidcentrifugally-actuated clutch shoes becoming operatively disengaged fromsaid clutch drum in response to the action of centrifugal force; andcontrol means responsive to torque and operatively connected betweensaid input means and said centrifugally-actuated clutch shoes forproducing a force component directed at a predetermined angle withrespect to the axis of said clutch shoes causing the reengagement ofsaid centrifugally-actuated clutch shoes with said clutch drum at alower predetermined speed than said above-mentioned predetermined inputspeed.
 5. The transmission described in claim 4, wherein said controlmeans includes a ramp of a predetermined angle formed on the radialouter surface of each of said clutch shoes, and a pin rotatably mountedintermediate each of said ramps and said input means.
 6. A transmissioncomprising an output shaft; an input pulley assembly including a pulleyhub rotatably mounted on said output shaft, an input pulley secured tosaid pulley hub, and a sleeve member formed on said pulley hub androtatably mounted on said output shaft; a planetary drive unit includinga fixed housing, a sun member mounted for rotation with said outputshaft, an outer ring member secured to said fixed housing, intermediateball members frictionally contacting said sun and outer ring members,and a carrier member for driving said ball members; a rotatable housingsecured to said pulley hub, a clutch drum rotatably mounted on saidsleeve member and connected for rotation with said carrier member; apair of oppositely disposed centrifugally-actuated clutch shoes mountedaround said clutch drum; spring means for urging saidcentrifugally-actuated clutch shoes into frictional engagement with saidclutch drum below a predetermined input speed; one-way clutch meansoperatively connected between said sleeve member and said output shaftfor operatively connecting said input pulley assembly to said outputshaft for direct drive of said output shaft at all speeds above saidpredetermined input speed upon said centrifugally-actuated clutch shoesbecoming disengaged from said clutch drum in response to the action ofcentrifugal force; and control means operatively connected between saidrotatable housing and said centrifugally-actuated clutch shoes forretaining said centrifugally-actuated clutch shoes in the disengagedposition until a lower predetermined speed than said above-mentionedpredetermined input speed is attained, said control means including aramp of a predetermined angle formed on the radial outer surface of eachof said clutch shoes, a pocket formed on the radial inner surface ofsaid rotatable housing, and a pin rotatably mounted intermediate each ofsaid ramps and said pocket.
 7. The transmission described in claim 6,and an air cooling system for automatically cooling said clutch drum andsaid clutch shoes.
 8. The transmission described in claim 7, whereinsaid air cooling system includes an opening formed in said rotatablehousing adjacent said fixed housing, a first plurality of taperedopenings formed through said clutch drum, and a second plurality oftapered openings formed in said rotatable housing adjacent said pulleyhub, said pulley assembly serving as a pump to continuously draw airthrough all of said openings to cool said clutch drum and said clutchshoes.
 9. The transmission described in claim 6, and a lubricationsystem for said planetary drive unit.
 10. The transmission described inclaim 9, wherein said lubrication system includes a predetermined volumeof a fluid medium contained in said fixed housing, slinger means formedon the radial outer edge of said carrier member, a plurality of radialopenings formed in the portion of said fixed housing supporting saidouter ring member, a chamber formed intermediate said portion of saidfixed housing and the outer wall of said fixed housing, a contouredportion formed on an inner end surface of said fixed housing adjacentsaid sun member, and a plurality of tapered openings formed through saidsun member, said carrier member and said slinger means serving toproject said fluid medium radially outwardly through said radialopenings into said chamber from whence said fluid medium returns underthe force of gravity to said contoured portion, said contoured portiondirecting said fluid medium into said tapered openings for pickup bysaid carrier member.
 11. The transmission described in claim 6, whereinsaid input pulley assembly serves as an output means, said output shaftserves as an input shaft.
 12. The transmission described in claim 4,wherein said control means includes wedge and slot means operativelymounted between said input means and said centrifugally-actuated clutchshoes.
 13. The transmission described in claim 12, wherein said wedgeand slot means includes a first pair of oppositely disposed slots eachhaving diverging side walls formed at predetermined angles in said inputmeans, a second slot having diverging side walls formed at predeterminedangles in each of said clutch shoes adjacent said respective first pairof slots, and a wedge mounted in each of said adjacent sets of first andsecond slots.
 14. The transmission described in claim 13, wherein saidwedges are rectangularly shaped with the edges along the length thereofbeing rounded off and said rounded-off edges being mounted in adjacentfirst and second slots for tilting therein as required to accommodatethe generally radial movement of said clutch shoes under the action ofcentrifugal force to effectuate the alternating contacts between saidinput means reaction member and said clutch shoes and between saidclutch shoes and said clutch drum at said different predeterminedspeeds.
 15. A transmission comprising input and output means;centrifugally-actuated clutch means for operatively connecting saidinput and output means when engaged; resilient means for normallycausing said centrifugally-actuated clutch means to remain engaged belowa predetermined input speed; and control means responsive to torque andoperating directly between said input means and saidcentrifugally-actuated clutch means and including, means for producing asubstantially radial engaging force resulting in the reengagement ofsaid centrifugally-actuated clutch means to occur at a lowerpredetermined speed than said above-mentioned predetermined input speed.16. A transmission comprising an input member; an output member; a hubmember intermediate said input and output members; a rotatable housingsecured to said input member, a clutch drum rotatably mounted on saidhub member and operatively connected to drive said output member; a pairof oppositely disposed centrifugally-actuated clutch shoes mountedarouNd said clutch drum; spring means for urging saidcentrifugally-actuated clutch shoes into frictional engagement with saidclutch drum below a predetermined input speed; and control meansoperatively connected between said rotatable housing and saidcentrifugally-actuated clutch shoes for retaining saidcentrifugally-actuated clutch shoes in the disengaged position until alower predetermined speed than said above-mentioned predetermined inputspeed is attained, said control means including a ramp of apredetermined angle formed on the radial outer surface of each of saidclutch shoes, a pocket formed on the radial inner surface of saidrotatable housing, and a pin rotatably mounted intermediate each of saidramps and said pocket.